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these five organs of sense. And the brain and nerve 
organism give us nothing but sensations. We can have no 
sensations, or feelings, which come in by the organs of sense, 
unless we have the organs. Nor can we form any idea of 
these sensations, or feelings, unless we have the organs. 
When the organs of sense are acted on ab extra they give 
us sensations, which are feelings, or mental states. More 
than this they cannot give us. And how the feeling arises in 
connection with the impression on the nerves of the different 
organs is a mystery, and likely to remain so. 
While the brain and nerve organism, through the organs of 
sense, furnish the mind with sensations only, their sound con- 
dition and healthy exercise are largely necessary to the 
functions of the faculties of the mind. 
Idea. 
“ An idea, or notion, is simply a feeling involving a refer- 
ence to some other thing.'”* “ And sensations neither 
become nor produce ideas of any kind; but merely present 
occasions for the exercise of other mental principles, by which 
the various ideas are formed."” 
The paper, however, seems to say that ideas, as well as 
sensations, come in by the brain as the organ of mind ; for it 
speaks of “ sensory and motor ideation, of auditory ideation, 
and of the revival of sensation in idea,”f aG d adds, cf the 
revival of a sensation in idea must possess essentially the 
same quality.” Ideation, however, is neither sensory, motor, 
nor auditory, but mental. 
A sensation cannot be revived in idea ; but, if you place 
yourself in circumstances exactly similar, you may have a 
sensation exactly similar to the former one. And the idea of 
a sensation does not possess essentially the same quality, and 
“ produce the same corporeal manifestations,” as were caused 
by the sensation itself. 
Again, the paper speaks of “the centres of sensory and 
motor ideation.”{ Ideation, however, belongs to mind : 
sensory and motor belong to brain and nerve matter. The 
one belongs to the psuche, the other to the phusis ; and, 
therefore, we cannot speak of sensory and motor ideation 
without confounding mind with brain matter. 
Again, it speaks of “ auditory ideation,” § and on the same 
page of auditory sensation. The one phrase is correct, the 
other not. The auditory sense furnishes us with auditory 
* Cairns’s Logic , p. 10. t Pages 122, 123. t Ibid. § Page 119. 
